Wednesday, July 18, 2007

Revolver Cylinder Puzzle

Yet another interesting puzzle :
Someone has kidnapped you and forced you to play a game of Russian Roulette ! Your kidnapper loads two bullets into adjacent chambers of an otherwise empty cylinder, and then spins the cylinder.

Then he presses the trigger ! Click ! Thankfully, the chamber was empty (this time!).

He then offers you a gamble : If you can survive the next round, he would set you free. To make it even better for you, he gives you two choices : One, he would spin the cylinder (randomly) before firing ; Two, he would just press the trigger now, without spinning.

Assuming that you would want to live through this encounter, what choice would you take? To spin or not to spin ?

Credits : Picture from howstuffworks , question from here.

Tuesday, July 17, 2007

Crazy Passenger Puzzle

Here's an interesting puzzle which I just encountered:
The Crazy Passenger

There are 100 airline passengers lining up to board the plane. They each hold a ticket to one of the 100 seats on that flight.

Unfortunately, the first person in line is crazy, and will ignore the seat number on his ticket, picking a random seat to occupy. All of the other passengers are quite normal, and will go to their proper seat unless it is already occupied. If it is occupied, they will then find a free seat to sit in, at random.

What is the probability that the last (100th) person to board the plane will sit in his proper seat?"

I found the puzzle (along with others) here. Unfortunately, I saw the numerical answer before giving the question much thought, but in my defense I did work out the solution almost immediately after.

Human Timeline

A poem from the dark abyss of my computer.
One o’clock,
Man learned to walk.
Two o’clock,
Man made tools from rock.
Three o’clock,
Man grew some plants.
Four o’clock,
Men learnt to chant.
Five o’clock,
Men lived in towns.
Six o’clock,
Men dealt with pounds.
Seven o’clock,
Men sailed the oceans.
Eight o’clock,
He made blasting potions.
Nine o’clock,
Came the Age of Steam.
Ten o’clock,
Life seemed like a dream.
Eleven o’clock,
Atoms were the game.
Twelve o’clock,
It never came.

Please pardon the unpolished state of this pseudo-poetry.